Akademik Veri Yönetim Sistemi
Turk Onkoloji Dergisi, cilt.40, sa.3, ss.218-224, 2025 (ESCI)
OBJECTIVE To compare reference-line (RL) and “inverse” optimization (IO) on organs at risk (OAR) and clinical target volume (CTV) doses in patients receiving vaginal cuff (VC) brachytherapy (BT). METHODS CT images of 20 patients were used who received VC BT using “Stump” applicator after external-beam RT (EBRT). Reference-line optimization (RLO) was performed to the line composed of 8 symmetrical points at 0.5cm from the applicator’s surface. Dose was prescribed to CTV in IO with introduction of optimization goals (CTV: D98%≥85%, D90%≥100%, V100%≥92.5%, and OARD2ccEQD2 total doses: Bladder ≤9000 cGy, rectum, sigmoid, and bowel ≤7000 cGy). Using Wilcoxon Signed-Rank test, 2 different optimization techniques were compared with respect to their effects on CTV dose-volume parameters and OAR D2cc. RESULTS Significantly lower D2ccEQD2 doses could be obtained with IO compared to RLO (p<0.001, p=0.004, p=0.001, and p=0.001 for bladder, rectum, sigmoid, and bowel, respectively). Significantly higher doses could be obtained with RLO for CTV D90% and V100% (p<0.001, and p<0.001, respectively). D%50/D%90 is significantly lower in IO (p<0.001). It was detected that CTV criteria could be met in all cases where OAR criteria of ≤7000cGy was violated only for rectum in 1 case in IO and 3 cases in RLO. CONCLUSION In both types of optimizations, desired criteria are met for CTV while they may not be met constantly in all cases. The resultant significant difference in favor of IO regarding OARs supports the routine clinical use of IO in VC BT.